I made this pedal for my buddy Jesse Crowe. It is a clone of the famed late 70's op-amp IC muff. Famous for being the secret weapon on Billy Corgan's guitar tracks on Smashing Pumpkin's Siamese Dream album. It is alot crunchier than your typical transistor gain stage big muff. The classic big muff fuzz circuit has 4 silicon transistor gain stages, and the IC MUFF uses 2 dual opamps to replace the gain stages a JRC4558D, and a μa741. The clipping is 3x1n914 diodes in series in each direction. It sounds like no other muff, and slamming the front end of a dirty JCM800 it nails the rhythm guitar tone from Siamese Dream. I used this layout.

The pedal is housed in a vertical Hammond 1590BB enclosure painted in Testor's Lime Ice. The graphic is an image of English mystic Aleister Crowley. The knobs are violet Davies 1510 and the LED water clear green.